From 13dae41c5708b4a7b74a0a043b34868a8363a78d Mon Sep 17 00:00:00 2001
From: Fabian <frznhope@gmail.com>
Date: Thu, 25 Apr 2019 16:34:03 +0200
Subject: [PATCH] Fabo/fix rounding issue in small number (#2487)

* fix rounding issue in small number

* added comment

* 'changelog'
---
 app/src/renderer/scripts/num.js     | 186 ++++++++++++++--------------
 changes/fao_fix-rounding            |   1 +
 test/unit/specs/scripts/num.spec.js |  98 +++++++--------
 3 files changed, 146 insertions(+), 139 deletions(-)
 create mode 100644 changes/fao_fix-rounding

diff --git a/app/src/renderer/scripts/num.js b/app/src/renderer/scripts/num.js
index 7441159dcb..5b40e693fd 100644
--- a/app/src/renderer/scripts/num.js
+++ b/app/src/renderer/scripts/num.js
@@ -1,90 +1,96 @@
-"use strict"
-import BigNumber from "bignumber.js"
-
-/**
- * Defines all numerical methods
- * @module num
- */
-
-export const SMALLEST = 1e-6
-const language = window.navigator.userLanguage || window.navigator.language
-export function full(number = 0) {
-  return new Intl.NumberFormat(language, { minimumFractionDigits: 6 })
-    .format(number)
-}
-export function shortNumber(number = 0) {
-  return new Intl.NumberFormat(language, { minimumFractionDigits: 4 }).format(number) + `…`
-}
-export function pretty(number = 0) {
-  return new Intl.NumberFormat(
-    language,
-    { minimumFractionDigits: 2, maximumFractionDigits: 2 }
-  ).format(Math.round(number * 100) / 100)
-}
-// pretty print long decimals not in scientific notation
-export function prettyDecimals(number = 0) {
-  let longDecimals = new Intl.NumberFormat(
-    language,
-    { minimumFractionDigits: 20, maximumFractionDigits: 20 }
-  ).format(number)
-
-  // remove all trailing zeros
-  while (longDecimals.charAt(longDecimals.length - 1) === `0`) {
-    longDecimals = longDecimals.substr(0, longDecimals.length - 1)
-  }
-
-  // remove decimal separator from whole numbers
-  if (Number.isNaN(Number(longDecimals.charAt(longDecimals.length - 1)))) {
-    longDecimals = longDecimals.substr(0, longDecimals.length - 1)
-  }
-
-  return longDecimals
-}
-export function prettyInt(number = 0) {
-  return new Intl.NumberFormat(language).format(Math.round(number))
-}
-export function percentInt(number = 0) {
-  return new Intl.NumberFormat(language).format(Math.round(number * 100)) + `%`
-}
-export function percent(number = 0) {
-  return new Intl.NumberFormat(
-    language,
-    { minimumFractionDigits: 2, maximumFractionDigits: 2 }
-  ).format(Math.round(number * 10000) / 100) + `%`
-}
-export function atoms(number = 0) {
-  return BigNumber(number).div(1e6).toNumber()
-}
-export function uatoms(number = 0) {
-  return BigNumber(number).times(1e6).toString()
-}
-
-// convert micro denoms like uatom to display denoms like ATOM
-export function viewDenom(denom) {
-  if (denom.charAt(0) === `u`) {
-    return denom.substr(1).toUpperCase()
-  }
-  return denom.toUpperCase()
-}
-
-export function viewCoin({ amount, denom }) {
-  return {
-    amount: full(atoms(amount)),
-    denom: viewDenom(denom)
-  }
-}
-
-export default {
-  SMALLEST,
-  atoms,
-  uatoms,
-  viewDenom,
-  viewCoin,
-  full,
-  shortNumber,
-  pretty,
-  prettyInt,
-  percent,
-  percentInt,
-  prettyDecimals
-}
+"use strict"
+import BigNumber from "bignumber.js"
+
+/**
+ * Defines all numerical methods
+ * @module num
+ */
+
+// truncate decimals to not round when using Intl.NumberFormat
+function truncate(number, digits) {
+  return Math.trunc(number * Math.pow(10, digits)) / Math.pow(10, digits)
+}
+
+export const SMALLEST = 1e-6
+const language = window.navigator.userLanguage || window.navigator.language
+export function full(number = 0) {
+  return new Intl.NumberFormat(language, { minimumFractionDigits: 6 })
+    .format(truncate(number, 6))
+}
+export function shortNumber(number = 0) {
+  return new Intl.NumberFormat(language, { minimumFractionDigits: 4 })
+    .format(truncate(number, 4)) + `…`
+}
+export function pretty(number = 0) {
+  return new Intl.NumberFormat(
+    language,
+    { minimumFractionDigits: 2, maximumFractionDigits: 2 }
+  ).format(Math.round(number * 100) / 100)
+}
+// pretty print long decimals not in scientific notation
+export function prettyDecimals(number = 0) {
+  let longDecimals = new Intl.NumberFormat(
+    language,
+    { minimumFractionDigits: 20, maximumFractionDigits: 20 }
+  ).format(number)
+
+  // remove all trailing zeros
+  while (longDecimals.charAt(longDecimals.length - 1) === `0`) {
+    longDecimals = longDecimals.substr(0, longDecimals.length - 1)
+  }
+
+  // remove decimal separator from whole numbers
+  if (Number.isNaN(Number(longDecimals.charAt(longDecimals.length - 1)))) {
+    longDecimals = longDecimals.substr(0, longDecimals.length - 1)
+  }
+
+  return longDecimals
+}
+export function prettyInt(number = 0) {
+  return new Intl.NumberFormat(language).format(Math.round(number))
+}
+export function percentInt(number = 0) {
+  return new Intl.NumberFormat(language).format(Math.round(number * 100)) + `%`
+}
+export function percent(number = 0) {
+  return new Intl.NumberFormat(
+    language,
+    { minimumFractionDigits: 2, maximumFractionDigits: 2 }
+  ).format(Math.round(number * 10000) / 100) + `%`
+}
+export function atoms(number = 0) {
+  return BigNumber(number).div(1e6).toNumber()
+}
+export function uatoms(number = 0) {
+  return BigNumber(number).times(1e6).toString()
+}
+
+// convert micro denoms like uatom to display denoms like ATOM
+export function viewDenom(denom) {
+  if (denom.charAt(0) === `u`) {
+    return denom.substr(1).toUpperCase()
+  }
+  return denom.toUpperCase()
+}
+
+export function viewCoin({ amount, denom }) {
+  return {
+    amount: full(atoms(amount)),
+    denom: viewDenom(denom)
+  }
+}
+
+export default {
+  SMALLEST,
+  atoms,
+  uatoms,
+  viewDenom,
+  viewCoin,
+  full,
+  shortNumber,
+  pretty,
+  prettyInt,
+  percent,
+  percentInt,
+  prettyDecimals
+}
diff --git a/changes/fao_fix-rounding b/changes/fao_fix-rounding
new file mode 100644
index 0000000000..71b7645e5d
--- /dev/null
+++ b/changes/fao_fix-rounding
@@ -0,0 +1 @@
+[Fixed] [#2487](https://github.com/cosmos/lunie/pull/2487) Remove rounding in small numbers @faboweb
\ No newline at end of file
diff --git a/test/unit/specs/scripts/num.spec.js b/test/unit/specs/scripts/num.spec.js
index 7aeaf2f388..6eb8c2e212 100644
--- a/test/unit/specs/scripts/num.spec.js
+++ b/test/unit/specs/scripts/num.spec.js
@@ -1,49 +1,49 @@
-import num from "renderer/scripts/num"
-
-describe(`number helper`, () => {
-  it(`should format numbers showing many decimals`, () => {
-    expect(num.full(1001950.123456)).toBe(`1,001,950.123456`)
-  })
-
-  it(`should format numbers showing many decimals`, () => {
-    expect(num.shortNumber(1.123456789)).toBe(`1.1235…`)
-  })
-
-  it(`should format numbers showing few decimals`, () => {
-    expect(num.pretty(1001950.123456)).toBe(`1,001,950.12`)
-  })
-
-  it(`should format numbers showing no decimals`, () => {
-    expect(num.prettyInt(1001950.123456)).toBe(`1,001,950`)
-  })
-
-  it(`should format percent without decimals`, () => {
-    expect(num.percentInt(0.2612)).toBe(`26%`)
-  })
-
-  it(`should format percent with decimals`, () => {
-    expect(num.percent(0.2612)).toBe(`26.12%`)
-  })
-
-  it(`should format long decimals well`, () => {
-    expect(num.prettyDecimals(1e-8)).toBe(`0.00000001`)
-  })
-
-  it(`should format long decimals well if whole number`, () => {
-    expect(num.prettyDecimals(12)).toBe(`12`)
-  })
-
-  it(`should convert utam denom to atom denom`, () => {
-    expect(num.viewDenom(`uatom`)).toBe(`ATOM`)
-  })
-
-  it(`should convert SDK coins to view coins`, () => {
-    expect(num.viewCoin({
-      denom: `uatom`,
-      amount: 1000000
-    })).toEqual({
-      denom: `ATOM`,
-      amount: `1.000000`
-    })
-  })
-})
+import num from "renderer/scripts/num"
+
+describe(`number helper`, () => {
+  it(`should format numbers showing many decimals`, () => {
+    expect(num.full(1001950.123456)).toBe(`1,001,950.123456`)
+  })
+
+  it(`should format numbers showing many decimals`, () => {
+    expect(num.shortNumber(1.123456789)).toBe(`1.1234…`)
+  })
+
+  it(`should format numbers showing few decimals`, () => {
+    expect(num.pretty(1001950.123456)).toBe(`1,001,950.12`)
+  })
+
+  it(`should format numbers showing no decimals`, () => {
+    expect(num.prettyInt(1001950.123456)).toBe(`1,001,950`)
+  })
+
+  it(`should format percent without decimals`, () => {
+    expect(num.percentInt(0.2612)).toBe(`26%`)
+  })
+
+  it(`should format percent with decimals`, () => {
+    expect(num.percent(0.2612)).toBe(`26.12%`)
+  })
+
+  it(`should format long decimals well`, () => {
+    expect(num.prettyDecimals(1e-8)).toBe(`0.00000001`)
+  })
+
+  it(`should format long decimals well if whole number`, () => {
+    expect(num.prettyDecimals(12)).toBe(`12`)
+  })
+
+  it(`should convert utam denom to atom denom`, () => {
+    expect(num.viewDenom(`uatom`)).toBe(`ATOM`)
+  })
+
+  it(`should convert SDK coins to view coins`, () => {
+    expect(num.viewCoin({
+      denom: `uatom`,
+      amount: 1000000
+    })).toEqual({
+      denom: `ATOM`,
+      amount: `1.000000`
+    })
+  })
+})